Two phenomena are being studied; these are susceptibility to audiogenic seizures and acoustic priming. With respect to audiogenic seizures we will attempt to study differences in serotonin and norepinephrine metabolism in seizure susceptible versus seizure resistant animals. Turnover of the amines and levels of enzymes in the biosynthesis of these biogenic amines will be measured. Manipulation of seizure susceptibility by drugs and diets will be studied. Neurophysiological and morphological differences between seizure resistant and seizure susceptible strains will be investigated. With respect to acoustic priming similar experiments will be attempted. The effects of the priming stimulus on the fine structure of the Organ of Corti will be accessed. Auditory evoked potentials will be measured in acoustically primed and control animals. The effects of acoustic priming on biogenic amines will be determined. The effects of protein synthesis inhibition on priming efficacy will be measured. Finally, genetic experiments will be undertaken in an attempt to determine the importance of genetic factors in priming efficacy.